1. Field of the Invention
The present invention relates to the field of reclosable packaging. More particularly, the present invention relates to a method of applying reclosable zippers to packages previously made on horizontal form-fill-seal OFFS) machines and vertical form-fill-seal (VFFS) machines.
2. Description of the Prior Art
Reclosable packages made on HFFS and VFFS machines are well known in the prior art. For example, U.S. Pat. No. 4,876,842 discloses a method of manufacturing reclosable packages on an HFFS machine, while U.S. Pat. Nos. 4,909,017, 4,655,862 and 4,894,975 disclose methods of manufacturing reclosable packages on VFFS machines.
These prior art methods, however, have proven unsatisfactory in certain circumstances. In particular, the disclosed methods are fairly complex in that they call for attachment of the reclosable zippers to the package material during formation, filling and sealing of the packages. This complexity in turn often necessitates the use of complex and expensive machinery in practice.